1. Field
The present invention relates to circuits and processes for authenticating and securing a transaction. More particularly, the invention relates to circuits and processes that enable a secure transaction responsive to interrogating an integrated circuit using an RF communication path.
2. Description of Related Art
The manufacturer or distributor of physical goods faces difficult problems in efficiently managing the distribution chain. The distribution chain, which may include distributors, shippers, warehousers, and retailers, each form an important link in bringing products to consumers. The manufacturer relies on the integrity of its distributors and retailers to assure that products are properly sold or otherwise delivered. Unfortunately, the distribution chain is often improperly managed, resulting in an ineffective path to market for the manufacturer's products. For example, products may be misappropriated by a corrupt distributor, by employees of the retailer, or by consumers. Manufacturers may also define distribution agreements with its distributors, where the manufacturer sets rules and restrictions on its distributors. These rules are typically used to assure that a fair distribution model is used, so that each distributor is able to maintain its profit margin, and to assure that consumers are satisfied with customer support. However, some retailers may try to avoid a manufacturer's distribution rules, and sell outside their designated market, or purchase products from an unauthorized source.
To better manage the distribution of products, manufacturers, distributors, and retailers have cooperated to implement a standard bar-coding process, UPC, to allow more automated tracking of inventory and products. However, the bar code label is used only to identify a class of product, so every item in that class has the same bar code indicator. While the UPC system has improved management of the distribution channel, additional information is needed. To fill some of the gaps in the UPC model, an RFID system has been proposed, and in limited cases, is being implemented. In the RFID system, a small integrated circuit is integrated into a tag, and the tag attached to a product. The circuit has sufficient memory that each tag can have a different value, thereby allow every product to be individually identified. In use, a unique value is stored into the tag, and the tag attached to the product. In the distribution chain, the product may be scanned by an RF reader, which reads the tag identifier. In this way, the product is tracked and monitored as it moves through the distribution chain. At the retail store, a consumer takes the product to a check stand, where the product is moved past another RF reader. The RF reader reads the tag identifier, and retrieves the price for the product. The sale is completed, and the product is removed from the store's inventory system.
The RFID system holds promise for providing much more information to manufactures, which will be useful in assisting in the control and management of the distribution process. However, the information stored on the RFID tag may be easily retrieved by commercially available readers, so can not be used to convey any sensitive information. Further, the tag and its circuit operate on the very limited power the circuit is able to derive from the RF signal, and must complete its operation as its being moved across a reader's RF field. This means that only limited computation can be performed due to power and time limitations, and that only a limited number of values can be communicated during the brief time the tag is energized. Accordingly, the tag's circuit is incapable of performing any meaningful encryption or decryption processes. In this way, the advances made in cryptography are not available to assist in securing tag-reader transactions.
Since the tag's information is subject to unauthorized access, no critical or vital information may be stored, thereby limiting the usefulness of the RFID system. What is needed then, is a way to better authenticate and secure the information conveyed from an RF integrated circuit. Such a system would greatly improve a manufacturer's ability to manage distribution of its products.